Hydralazine hydrochloride MCQs With Answer is a focused study resource for B. Pharm students covering pharmacology, mechanism of action, pharmacokinetics, indications, dosing, adverse effects and drug interactions of hydralazine. This vasodilator primarily relaxes arteriolar smooth muscle to reduce afterload and is metabolized by hepatic N‑acetylation, producing variable responses in slow and fast acetylators. Key clinical points include its use in severe hypertension, hypertensive emergencies in pregnancy, and as adjunctive therapy in heart failure with nitrates, plus the risk of reflex tachycardia, fluid retention and drug‑induced lupus. These concise, exam‑oriented MCQs will deepen your understanding of therapeutics, monitoring and safe prescribing. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary mechanism of action of hydralazine?
- Inhibition of angiotensin converting enzyme
- Direct relaxation of arteriolar smooth muscle reducing afterload
- Blockade of beta‑adrenergic receptors
- Inhibition of calcium channels in cardiac myocytes
Correct Answer: Direct relaxation of arteriolar smooth muscle reducing afterload
Q2. How is hydralazine primarily metabolized in the body?
- Glucuronidation in the intestine
- Renal excretion unchanged
- Hepatic N‑acetylation by N‑acetyltransferase
- Oxidation by CYP3A4
Correct Answer: Hepatic N‑acetylation by N‑acetyltransferase
Q3. Which adverse effect is characteristically associated with long‑term hydralazine therapy?
- Ototoxicity
- Drug‑induced lupus erythematosus‑like syndrome
- Thrombocytopenia
- Hyperkalemia
Correct Answer: Drug‑induced lupus erythematosus‑like syndrome
Q4. Hydralazine‑induced lupus is more likely in which pharmacogenetic phenotype?
- Ultra‑rapid metabolizers
- Slow acetylators
- Fast acetylators
- Poor oxidizers by CYP2D6
Correct Answer: Slow acetylators
Q5. Which clinical situation commonly warrants IV hydralazine administration?
- Mild essential hypertension controlled with diet
- Hypertensive emergency in pregnancy
- Routine outpatient blood pressure control
- Isolated orthostatic hypotension
Correct Answer: Hypertensive emergency in pregnancy
Q6. Hydralazine is often combined with a nitrate in heart failure because:
- Both drugs increase renal perfusion directly
- Hydralazine reduces preload and nitrates increase afterload
- Hydralazine reduces afterload while nitrates reduce preload, improving cardiac output
- The combination blocks renin secretion synergistically
Correct Answer: Hydralazine reduces afterload while nitrates reduce preload, improving cardiac output
Q7. Which co‑medication is commonly used with hydralazine to blunt reflex tachycardia?
- Loop diuretic
- Beta‑blocker
- ACE inhibitor
- Calcium supplement
Correct Answer: Beta‑blocker
Q8. A major clinical caution when using hydralazine is worsening of which condition?
- Asthma
- Coronary artery disease with angina
- Hypothyroidism
- Hyperlipidemia
Correct Answer: Coronary artery disease with angina
Q9. Which route of administration provides the fastest onset of action for hydralazine?
- Oral immediate‑release tablet
- Transdermal patch
- Intravenous bolus
- Intramuscular injection
Correct Answer: Intravenous bolus
Q10. Typical onset of antihypertensive effect after an oral dose of hydralazine is approximately:
- 5–10 minutes
- 20–60 minutes
- 6–8 hours
- 24 hours
Correct Answer: 20–60 minutes
Q11. The plasma half‑life of hydralazine is prolonged in which patient group?
- Fast acetylators
- Patients with increased CYP3A4 activity
- Slow acetylators
- Patients on enzyme‑inducing anticonvulsants
Correct Answer: Slow acetylators
Q12. Which serologic marker is most commonly positive in hydralazine‑induced lupus?
- Anti‑dsDNA antibodies
- Anti‑histone antibodies
- Anti‑CCP antibodies
- Anti‑SM antibodies
Correct Answer: Anti‑histone antibodies
Q13. Essential monitoring while a patient is on chronic hydralazine therapy should include:
- Serial blood cultures
- Blood pressure, heart rate and signs/symptoms of drug‑induced lupus
- Daily blood glucose measurements
- Serum digoxin levels
Correct Answer: Blood pressure, heart rate and signs/symptoms of drug‑induced lupus
Q14. Which of the following drug interactions is therapeutically useful with hydralazine?
- Combining with beta‑blocker to prevent reflex tachycardia
- Combining with nitrates to increase preload
- Combining with calcium supplements to boost effect
- Combining with NSAIDs to enhance vasodilation
Correct Answer: Combining with beta‑blocker to prevent reflex tachycardia
Q15. Pharmacologically, hydralazine is classified as a:
- Peripheral alpha‑1 blocker
- Direct arteriolar vasodilator
- Thiazide diuretic
- Central alpha‑2 agonist
Correct Answer: Direct arteriolar vasodilator
Q16. Common dosage form(s) available for hydralazine include:
- Oral tablets and intravenous injection
- Topical cream only
- Inhalation aerosol
- Subcutaneous implant
Correct Answer: Oral tablets and intravenous injection
Q17. Which acute side effect is frequently reported after initiating hydralazine therapy due to vasodilation?
- Bradycardia
- Headache
- Hypersalivation
- Ocular hemorrhage
Correct Answer: Headache
Q18. In the management of severe pre‑eclampsia or eclampsia, hydralazine is considered:
- Contraindicated and never used
- One of the recommended parenteral antihypertensives
- Only used topically
- Replaced by oral diuretics as first line
Correct Answer: One of the recommended parenteral antihypertensives
Q19. Hydralazine predominantly affects which component of the cardiovascular system?
- Venous capacitance vessels to decrease preload
- Arterioles to decrease systemic vascular resistance
- Cardiac conduction system to slow AV node conduction
- Platelets to inhibit aggregation
Correct Answer: Arterioles to decrease systemic vascular resistance
Q20. A clinical phenomenon that may reduce hydralazine effectiveness over time due to neurohormonal activation is called:
- Tachyphylaxis
- Idiosyncratic reaction
- Photoallergy
- Allergic desensitization
Correct Answer: Tachyphylaxis
Q21. The combination of hydralazine and isosorbide dinitrate (BiDil) is particularly indicated for:
- Diabetic neuropathy
- Heart failure in selected patient populations
- Primary prevention of stroke in young adults
- Acute management of asthma
Correct Answer: Heart failure in selected patient populations
Q22. Which laboratory test is most useful if drug‑induced lupus is suspected during hydralazine therapy?
- Serum creatinine kinase
- Anti‑histone antibody assay
- Serum amylase
- Fasting lipid profile
Correct Answer: Anti‑histone antibody assay
Q23. Typical oral dosing frequency for hydralazine in chronic hypertension is:
- Once weekly
- Once daily
- Two to three times daily (BID/TID)
- Every 8 seconds via continuous infusion
Correct Answer: Two to three times daily (BID/TID)
Q24. Which specific enzyme genotype influences hydralazine metabolism?
- CYP2C19 polymorphism
- N‑acetyltransferase 2 (NAT2) polymorphism
- CYP1A2 polymorphism
- UDP‑glucuronosyltransferase polymorphism
Correct Answer: N‑acetyltransferase 2 (NAT2) polymorphism
Q25. Hydralazine should be used with caution or is relatively contraindicated in patients with:
- Stable hypothyroidism
- Severe coronary artery disease and unstable angina
- Mild eczema
- History of gout
Correct Answer: Severe coronary artery disease and unstable angina
Q26. Reflex tachycardia following hydralazine administration is primarily mediated by:
- Direct stimulation of SA node by drug metabolites
- Baroreceptor‑mediated sympathetic activation
- Inhibition of vagal tone in the gastrointestinal tract
- Increase in central acetylcholine release
Correct Answer: Baroreceptor‑mediated sympathetic activation
Q27. Long‑term manifestations of hydralazine‑induced lupus typically include which symptoms?
- Arthralgia, myalgia and fever
- Persistent cough and hemoptysis
- Yellowing of skin and sclera
- Peripheral neuropathy with sensory loss
Correct Answer: Arthralgia, myalgia and fever
Q28. At the cellular level, hydralazine lowers vascular tone mainly by:
- Enhancing calcium influx into smooth muscle cells
- Altering intracellular calcium handling and promoting smooth muscle relaxation
- Blocking sodium channels in vascular endothelium
- Stimulating endothelin release
Correct Answer: Altering intracellular calcium handling and promoting smooth muscle relaxation
Q29. Which of the following is a primary clinical indication for hydralazine?
- Chronic management of hyperlipidemia
- Severe hypertension not controlled by first‑line agents and hypertensive emergencies in pregnancy
- Primary treatment of atrial fibrillation
- Bacterial endocarditis prophylaxis
Correct Answer: Severe hypertension not controlled by first‑line agents and hypertensive emergencies in pregnancy
Q30. During long‑term therapy with hydralazine, clinicians should periodically assess the patient for:
- Signs of drug‑induced lupus, degree of tachycardia and blood pressure control
- Daily urine ketones
- Serum magnesium levels every 6 hours
- Visual acuity monthly
Correct Answer: Signs of drug‑induced lupus, degree of tachycardia and blood pressure control
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